This section is intended to provide a background or context to the invention disclosed below. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise explicitly indicated herein, what is described in this section is not prior art to the description in this application and is not admitted to be prior art by inclusion in this section.
The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:                1xRTT 1x Radio Transmission Technology (a CDMA2000 technology)        3GPP Third Generation Partnership Project        CDMA Code Division Multiple Access        CDMA2000 Code Division Multiple Access 2000        CS Circuit Switched        CSFB Circuit Switched FallBack        eNodeB or eNB E-UTRAN (or evolved) NodeB (LTE base station)        EPC Evolved Packet Core        E-UTRAN Evolved UTRAN        HRPD High Rate Packet Data (a CDMA2000 technology)        eHRPD evolved HRPD (a CDMA2000 technology)        ID IDentification        IWS InterWorking Solution        LTE Long Term Evolution        MME Mobility Management Entity        NAS Non Access Stratum        NID Network IDentity        PLMN Public Land Mobile Network        PRL Preferred Roaming List        RAN Radio Access Network        RAT Radio Access Technology        RRC Radio Resource Control        S1AP S1 Application Part        SIB1 System Information Block type1        SIB8 System Information Block type8        SID System IDentity (or System IDentifier)        SRVCC Single Radio Voice Call Continuity        TS Technical Standard        UE User Equipment        UTRAN Universal Terrestrial Radio Access Network        VoIP Voice Over Internet Protocol        
Current LTE specifications only support interworking (e.g., Handover, CSFB, SRVCC procedures) between a single LTE system and a single CDMA2000 system of each type (1xRTT and eHRPD). There is a need to support interworking between a single LTE system and multiple CDMA2000 systems of the same type, to accommodate cases where one LTE system has overlapping radio coverage with multiple CDMA2000 systems of the same type.